The present invention relates to a method and apparatus for harvesting crops and more particularly to such a method and apparatus particularly well suited to the harvesting of mushrooms grown on a commercial scale which have conventionally required repetitious manual harvesting operations.
As the commercial demand for mushrooms has expanded, considerable effort has been directed to the development of mechanical harvesting devices capable of eliminating the necessity for manual harvesting of the product. Although the prior art, as typified by the Verhoff U.S. Pat. No. 1,787,026; the Schumacher U.S. Pat. No. 2,202,433; the Sinden et al U.S. Pat. No. 3,624,990; the Persson U.S. Pat. No. 3,635,005; and the Bradbury U.S. Pat. No. 3,679,002, evidences several devices reputed to permit such automated harvesting of mushrooms, considerable difficulties reside in their operation which have prevented the general use of such devices by the industry. These problems are believed to have been overcome by the method and apparatus of the present invention.
Mushrooms are grown in enclosures naturally or artificially possessing the appropriate environmental conditions of humidity, temperature, and low illumination conducive to their rapid growth and efficient production. Efficiency directs that every available area within the enclosure be utilized for growing of the mushrooms. Consequently, the mushrooms are grown commercially in tables containing a growing medium disposed in horizontal tiers vertically separated by distances of approximately 12 inches permitting access to the mushrooms for harvesting.
In optimum environmental conditions, mushrooms grow rapidly and frequently double or triple in size in a 24-hour period. Consequently, the mushrooms must ordinarily be harvested on a daily basis in order to produce mushrooms of uniform quality. Such rapid growth has conventionally required manual harvesting in order to allow discriminate selection of only uniformly mature mushrooms. This is accomplished with the aid of an artificial light source, by reaching between the tiers to pick those mushrooms, determined by visual observation, to be of a mature size suitable for harvesting. This is a laborious and inefficient operation since the mushrooms are frequently difficult to reach between the tiers, they are easily damaged by contact during harvesting, and it is often difficult rapidly to observe which mushrooms are of a mature quality because of the limited space between the tiers.
Thus, it has long been realized that the development of a reliable method and apparatus for harvesting crops, such as mushrooms, capable of discriminately harvesting only those crops of a predetermined maturity without damage either to the harvested crops or to those passed over would be of considerable value to the industry in reducing the expense of production while improving the uniformity of the quality of the harvested crops and assisting in permitting the expansion of production.